We need jobs for everyone for various reasons. However we do not need factory jobs for everyone. The manufacture more with less people means those other people can move on to other jobs. They can start another factory to make goods.

There are plenty of jobs. Every person who isn't manufacturing is a person who can do something else. A modern car uses a lot more engineers. While we don't need many spa mangers, it is nice that spas exist and so some of those spa managers are needed.